Shock absorber



J. R. SNYDER SHOCK ABSORBER 1 Dec. 6, 1932.

Original Filed Aug. 9, 1924 Patented Dec. 6, 1932 UNITED STATES insanerecon n. SN'YDER, or CLEVELAND, omo

SHOCK ABSORBER Application filed August 9, 1924, Serial No. 731,016.Renewed April 21, 1932.

rlhis invention relates to'improvements in yshock absorbers, Y adaptedparticularly for use on motor vehicles to check the rebound movement ofthe main springs.

The object of the invention is to vprovide a-novel and etlicientvconstruction of a shock absorber of the frict-ionally retarded type.

More particularly the invention aims to provide a shock absorber of thetype wherein there is a frictionally retarded Vrotary member onto whicha strap is Wound and from which it is unwound, and having frictionretarding means, the construction and applica# tion of which is animprovement over the friction imposing means heretofore utilized.

In this connection it is the aim of the invention to provide meanswhereby there is an effectively regulated friction resistance whichVaries at different points/in the cycle of operat-ion of the shockabsorber, and which retards the rotary member during the rebound stroketo a greater extent than during the compression stroke of the mainspring.

Other objects are attained by my invention which may be here brieflysummarized as consisting in certain novel details of construction, andcombinations and arrangements of parts which will be described in thespecification and set forth in the appended claims.

In the accompanying sheet ofV drawings wherein I have shown thepreferred embodiment of the invention, Fig. 1 is a side elevation of theshock absorber; Fig. 2 is a sectional view at right angles to theaXis,\the same being shown on an enlarged scale; Fig. 3 is a sectionalview at right angles to the section of F ig. 2; and Fig. 4 is a detailsec-v tional view substantiallyalong the line 4; ofFig.2. Y Referringnow to the drawing', r1() represents a stationary center bolt which inthe ordinary use of the device is securedto the chassis frame of thevehicle by a fitting screwed ontothe reduced end 100 of the center bolt.Additionally the device included a stationary casing composed in thisinstance of two portions 11 and 12. As here shown, the part 11 is in theform of a disk which forms one side of the casing. The part 12 forms thevmovement of the main springs.

. portion of the casing formed by the two parts l1 and 12 is somewhatwider than the inner portion, the fouter part being extendedlaterally toform a support for the frictionally 60 retarded rotatable member.

Surrounding the center bolt and located Within the inner or narrowerpart of the casing is a 'spiral spring 14,' and outwardly of thespringis the rotatable frictionallyl retard- 65 ed member in the form of anannulus or rin 1.5 which is preferably formed of self-lubricatingmaterial such as oil impregnated Wood, and is supported bythe two parts11 and 12 of the casing on shoulders 16 which may be 70 inclined asshown or square. The outer end of the spring is attached to the annulus15 by a fastening device which may be in the form of a rivet 17 (seeFig. 2). Theinner surface of the ring Wherethe rivet passes 75 throughit is Vpreferably faced for a suitable distance with a metal .strip orlinsert 18 throughone end of which the rivet 17 passes. The opposite endmay be held to the drum by a-rivet or equivalent device 19. It might 50be here stated that the function of this spring is, of course, to rotatethe annulus 15 to wind thereon the vstrap during the compression Theinner end of the spring 14 is stationary m) and is preferably secured inany suitable way to a collar 2O surrounding the center bolt 10. 1n thisinstance the end ofthe spring isfat- Y tached to the collar'by a pin orblock v21 eXf oo tending into a suitable opening formed inthe collar. y'y One end of this collar bears against the inv ner orcentral'portionof'the'oasing part or vdisk 11 which is clamped against ashoulder of 95 the center bolt by a nut 22 screwed onto the reduced end10c of the center bolt, to which nut thev disk 11 is in this instanceriveted.l The opposite end of the collar 2O has an eX- v tension 20awhich projects outbeyond the 109 y casing, the part 12 of the casingbeing fitted onto this extension as shown. Y

The annulus is adapted to have connected to it. the inner end of a strap23 which extends out through an opening in the peripheral part of thecasing and is designed to be connected to the axle. In this instance theinner end of the strap is connected toa pin 24 which is mounted in earsof a pair of small instal clips or brackets 25 which, are secured to theouter surface of the annulus 15 near its sides.

The strap 23 does not directly engage the annulus 15, but interposedbetween the stra-p and the a-nnulus is a stationary friction member26 inthe form of a band,which isl wrapped around the annulus for thermajorportion of its circumference. One end of the band 26 is held stationaryby being hooked around a pin 27 which extends between the sides of thecas ingoutside or beyond the annulus 15, this being clearly illustratedin Figs. 2 and 3. The other end of the band 26 is free, as shown in Fig.2, this band extending from its fixed end around the peripheryof theannulus in the same direction that the strap 23 extends from the pin 24.

The strap 23 bears upon and is ydesigned to be wrapped on the band 26,and inasmuch as the band 26 is stationary, it is obvious that when theannulus is rotated it will friction ally engage the inner surface of theband 26, and at the same time the strap 23 will frictionally engage orslide over the outer surface ofthe band 26.

It will be apparent that during the compression stroke of the mainspring, during which time the spring 14 rotates thev annulus 15 so asrto wind in the strap, there is practically no load on the strap, inconsequence of which the strap will slide freely overthe band 26, whichtherefore offers practically no resistance to the winding in of thestrap.'

Furthermore., during this part of the cycle, the strap 23 does not pressthe band down against the annulus, and whatever frictional resistancethere may be between the strap and band is exerted in a direction towardor against the anchored end with the result that it has a tendency toloosen the band on'the annulus. The band is thus released from theannulus, and this is preferably enhanced either by so forming the bandthat it has a natural or inherent tendency to open up or spread awayfrom the annulus, as by forming it` of steel or other material having asuitable spring or elasticity, 'or by providing a spring or other deviceextraneous to the band for opening it when it is relieved of pressure bythe belt. Such an arrangement is shownl in Fig. 2 wherein a spring 28acts on the free end of the band so as to open it. This spring surroundsa pin'or screw 29 having threaded engagement with the pin 27 and one yofits ends bears against the free end of band 26 while its other endengages an abutment in the form of an adjustable nut 30 on the screw 29.

However, during the rebound stroke there is a considerable load on strap23, and the effect of this is to cause a pressure on the band 26 and atthe same time pull the band down against the surface of the annulus withthe result that the rebound movement is retarded by the friction of thedrum on the band and bythe friction of the strap on the band.Additionally, of course, the spring 14 is woundup during this part ofthe cycle of operations, and the gradually increased tension imposed inthe spring also has a tendency to check the rebound. From the above itwill be seen that notwithstanding the fact that the annulus 15 rotatesrelative to the friction member 26 during bothv the compression andrebound movements of the main springs'fof the vehicle, nevertheless itfrictionally resists the rotation of the annulus 15 only in one di'-rection, or during the rebound stroke. By reason of thesecharacteristics and new function the band 26 may be aptly termed afloatingfriction member.

In addition to the above I have provided a novel and effective means foradjusting the normal tension of the spring 14. This includes a ratchetor ratchet disk 31'which is fitted onto the extension 20a of the collar20 on the outer side of the casing part 12, and it is in any convenientway held from rotating on the collar. A pawl 32, carri-ed by the casing,engages the ratchet 31V in such a way as to normally prevent the springfrom unwinding by turning the collar. The parts are normally held inproperly assembled rela# tionship'bya nut 33 screwed onto the centerbolt, this nut pressing the ratchet 31 against the side of the casingand the latter holding the casing part 12 against a shoulder of thecollar. Any suitable lock nut may be provided for preventing the nut 33turning, andV4 in this instance I show a common'lock nut in the form ofa washer 34 arranged between the nut 33 and ratchet 31, this washerhaving alip bent over one face of the nut to hold itv against movement.If it is desired to vary the tension of the spring, the nut 33 is backedaway by first bending up the lip of the nut locking washer 34, and thenby turning -the ratchet 31 with a suitable tool appliedthereto. In thisway the tension of the spring 14 can be either increased or decreased.

If it is desired to vary the normal'distauce that thestrap 23is wrappedaround the band 26, this can be readily done by looseningthe shockabsorber at the point where the nut 22 engages the fitting by which theshock absorber is fastened to the chassis frame and by angularly turningthe shock absorber in one direction or another and then reclamping thenut 22 to the fitting. It will then become desirable to adjust the part12 of the casing with reference tothe part 1.1 so `as Ito bring` theperipheral opening through y.w-hich .the strap 23 extends ,fromvthe'casingiat the right point :to permit f-ree movement lof the strap23 into andout ofthe casing. Toiaccomplish this, the nut 33 is loosened,thezpart 12\of the .casing is disengaged from the part 11 and -is thenturned until the .peripheral opening of the part 12 is in .the rightposition Aand then the parts are reclamped together. rIlo permit thisrela-tive shifting of .the stwo parts of the casing, .the part 12 of theJcasing is provided with aser-ies of openings 35, -in any one of whichthe end of Ipin 24 which receives-'fthe end of the strap 23 may beinserted, pi-n 24 -being freely disengageable from :and insertible inany one of the openings .35 provided .in the side of the part 12 of thelcas-ing.

In Fig. 4, I show a :bridge 36 for supporting the outer convolutionvofspring 14 .ata suitable distance from the point where its outer endis connected to rivet 17. In this instance .the bridge 36 ,is in the'form of a loop. which passes underneath the metal clip or `strip 18,one portion of the loop passing bunder the outer convolution of thespring. Tliisbri'dge keeps the form or body of the spring substantiallycoaxial with the center'b'olt, and prevents the iiexing of the lspringnear the point where it is connected to rivet 17. This in turn avoidscrystallization and increases the life of the spring.

In conclusion it might be mentioned that lubricant may be supplied tothe ,space between the side members of the casing occupied by spring 14so as to lubricate.itsconvolutions and render it silent in action. Thislubricant can be supplied through an axially disposed opening 37, theouter end being normally closed by a plug 38, and its inner endcommunicating through a suitable opening in the collar 20 with the spacein thecasing occupied by spring 14.

Having described my invention, I claim:

l. In 'a shock absorber, a rotary member, a strap connected thereto andadapted to be wound onto and unwound therefrom, and a floating frictionmember between the rotary member and the strap and engaging the rotarymember.

2. In a shock absorber, an annular rotatable member, a strap connectedthereto and adapt-l ed to be wound onto and unwound therefrom, and afriction member adapted to engage the rotatable member and locatedbetween the strap-and annular member and having one end only xed.

3. In a shock absorber, a rotatable member, a strap connected theretoand adapted to be wound onto and unwound therefrom, anda floatingfriction band enveloping` the rotatable member and engageable therewithand arranged between the latter and the strap.

4. In a shock absorber, a rotatable member, a strap connected theretoand adaptedto be wound onto and unwou-nd therefrom, and-a stat-ionaryfriction member envelopingfthe -rotatable Imember so that it mayfrictionally "engage the same `and havingo'neend fixed and itsopposrteend free to come and go.V Y

5. Ina shock absorber, a rotatable member,

fixed and enveloping the rotatable member between the latter andthestrap, said friction ymember adapted to frictionally` grip `therotatable'member when the latter is turned in one direction by the strapand to be relatively free on the rotatable member when the latter isturned to Wind the strap thereon.

56. In a shock absorber, a rotatable member, a spring connected theretoto turn the sa-me in one direction, a'straplconnected to 4said member torotate it inthe opposite .-direction, and a floating friction memberenveloping the rotatable member so that it may fri-ctionally engage thesame and arranged between the latter `and the strap. y

7. In al shock absorber, a rotatable member, a spring within the sameand connected thereto so as to rotate it in one direction, a stra-pconnected to said memberv andv adapted to be wound onto and to beunwound therefrom, and a stationary friction band extending about saidmember between the latter and the strap so that it mayfriction-ally-'engage said member and adapted to ,alternately grip 'andrelease said member as its direction of rotation is changed.

8. In a shock absorber', a center bolt, a springsurrounding the centerbolt and having its inner end fixed, a rotatable annulus supported at adistance from the rcenter bolt and surrounding the spring, the latterhaving its outer end connected to the annulus, a strap Vconnected to theannulus and adapted to be wound onto and unwound therefromV and meansfor creating a friction on said annulus when it is rotated in onedirection'.

9. In a shock absorber, astationary center bolt, a stationary` casing, aspring surrounding the center bolt and having its inner end fixed, arotatable annulus supported by the casing outside rof the spring, thelatter having its outer end connected to the annulus, a strap connectedto theannulusan'd adapted to be vwound onto and unwound therefrom, and afriction member adapted to engage said annulus. l Y

10. In a shock absorber, a stationary casing and a stationary centerbolt, the former having two opposite sides, a spring surrounding thecenter bolt andhaving its innerend connected thereto, .an annulussupported on shoulders of the casing outwardly' of theA center bolt andspring, the annulus surroundingthe spring yand having a connection withthe outer end of the latter, and a strap adaptdirection only.

tatable drum, a strap` connected thereto and adapted to be Wound aboutthey same .and to be unwound Jtherefrom, and a: friction member, bothsides of which areeffective to frictionally resist the unvvinding, ofthe strap, the fric'- tional resistance offered by one side beingvariable.

'12. In a shock absorber, a rotatable drum, a strap connectedv theretoandadaptedto be Wound about the same and tobe unwound therefrom, andA afriction member, the inner and outer` sides of Which are effective tofri'- tionally resist the unwinding' of the strap', the frictionalresistance created by the outer side being variable. i

13. In,Y a shock absorber, a rotatable drum, a. strap connectedtheretofand 'adapted to be Wound about the same and to be unvvoundtherefrom, and a friction member, the inner and outer sides of Which areeffective to frictionally resist the unwinding of the'strap, theeffective frictional area ofv the-outer side being varied asthe strapunwinds. e l 14. In a shock absorber, a member rotatable in oppositedirections, a strap adapted to be Wound about the .same and to beun-Wound therefrom, and fa flexible friction member With respect to whichsaid rotary member rotates in both directions and Which is effective byengagement with said rotatable member to resist the rotation thereof inone l5. In a shock absorber, a member rotatable in opposite directions,a strap-adapted to be Wound about the same and to be unwound therefrom,and afiexible friction member with respect to which the said rotarymember rotates in both directions, the friction member vfrictionallyengaging the rotary member when it rotates in one direction, and beingreleased therefrom When it rotates in i the opposite direction.

16. In a shock absorber, a rotary member, a strap connected thereto andadapted to be Wound aboutk they same and to be unwound therefrom as thesaid member rotates in opposite directions, and a fiexible frictionmember Which is caused by the strap torfrictionally engage the rotarymember when the strap is unwound from the latter.

17. In a shock absorber, a rotary member, a'strap connected thereto andadapted to be Wound about the same and to be unwound therefrom as saidmember isrotated in opposite directions, and a flexible friction memberwhich frictio-nally resists the unwinding movement of the strap and iscausedby the strap to frictionally lengage said rotary mem*- ber as itrotates to permit the strap to be unwound. f

18. In a shock absorber, a rotary member, a Vstrap connected thereto andadapted tobe Wound about the same 4and to be unwound therefrom as saidmember isrotatedin opposite directions, anda flexible friction memberwhich frictionally opposes the movement of the strap offthe rotarymember and also engages and frictionally yopposes said vrotary memberduring the unwinding of the strap. 19. Ina shock absorber, a rotarymember,

a strap adapted to be Wound about the same 20. In a shock absorber, amember rotatable in opposite directions, a spring connected to saidmember to rotate the same in one direction, a strap. connected to saidmember and adapted tobe Wound onto and unwound therefrom, andv afloating friction member which frictionally Vengages the rotatablemember to oppose its rotation in one direction butv permits relativelyfree rotation in the opposite direction. 21. In a shock absorber, amember rotatable in opposite directions, a spring connected thereto andserving to rotate it in one direction, a strap adapted to be Wound ontoand unwound from saidl member, and ay floating friction-creating memberengaging the periphery of the rotatable member and serving to'resistYits rotation in one direction and permitting relatively free rotationin the opposite direction. f v l 22. In a shock absorber, a drumrotatable in opposite directions, a strap adapted to be Wound onto andunwound therefrom, a spring connected to -the drum to rotate it in Vonedirection, and a floating eXpansible and contractible friction elementengaging the drum and serving to frictionally resist the rotation of thedrum When the strap is unwound'there# from and permitting relativelyfree rotation of the drum when the strap is Wound thereon by therotation of the drum under the action of the spring. V i i 23. In ashock absorber, a. drum rotatable in opposite directions, a strapadapted to be Wound onto and to be unwound from the peripheral portionthereof and an expansible and contractible floating friction memberengaging the peripheral part of the drum and serving to resist therotation of the drum When it is rotated in one direction and permittingrelatively 'free rotation in theopposite direction.

24. In a shock absorber, a drum rotatable in opposite directions, astrap connected thereto and adapted to be Wound onto and unvvoundtherefrom,v a spring connectedto the drum and servingto rotate the samein one direction, and an eXpansible and contractible friction memberWith respect to which the drum rotates in both directions kand whichautomatically engages the drum to frictionally resist its rotation inone direction and automatically releases itself from the drum to permitrelatively free rotation in the opposite direction.

25. In a shock absorber, a drum rotatable in opposite directions, astrap adapted to be wound onto and unwound therefrom, a spring connectedto the drum for rotating the same in one direction, and an Vexpansibleand contractible friction member with respect to which the drum rotatesin both directions and which automatically engages the peripheral partof the drum to frictionally resist its rotation in one direction and isautomatically released from the drum to permit relatively free rotationin the opposite direction.

26. In a shook absorber, a drum, a strap adapted to be wound onto andunwound therefrom, a spring for rotating the drum in one direction and aiioating friction member enga-geable with a portion of the drum andserving to retard the rotation of the drum as the strap is unwound, saidfriction member during suoli movement of the drum having one of its ends`held stationary and having a portion at a distance from such endpressed against the drum.

27. In a shock absorber, a drum rotatable in opposite directions, astrap adapted to be woundV onto and unwound therefrom, a spring forrotating the drum in vone direction, a floating friction member arrangedcircumferentially of the drum and in contact with said strap, a stopmember for holding one end of the friction member stationary, and meanswhereby said friction member is caused to automatically frictionallyengage and to be released from the drum depnding upon the direction ofrotation thereo Y 28. In a shock absorber, a rotatable member, a strapconnected thereto and adapted to be wound onto and unwound therefrom,and a friction member interposed between the strap and rotatable memberand extending about the same, said member having one end fixed and beinginherently flexible so as to frictionally grip the rotatable memberunder the pressure of the strap and to release the rotatable member whenthe strap pressure is released.

29. In a shock absorber for vehicles, a rotary member, a strap connectedthereto and adapted to be wound about the same and to be unwoundtherefrom, and a flexible inherently elastic friction member whichengages said rotary member and both sides of which are effective tofrictionally resist the unwinding of the strap.

30. In a shock absorber, a member rotatable in opposite directions, astrap adapted to be wound about the same and to be unwound therefrom,and a flexible inherently elastic friction member with respect to whichsaid rotary member rotates in both directions and which is effective tofrictionally engage and resist the rotation of said rotary member in onedirection only.

31. In a shock absorber, a member rotatable in opposite directions, astrap adapted to be wound about the same and to be unwound therefrom,and an inherently elastic friction member Vwith respect to which saidrotary member rotates in both directions, the friction memberfrictionally .engaging the rotary member when it rotates in onedirection and releasing itself therefrom whenit rotates in the oppositedirection. y

32. In a shock absorber, a rotary member,

a strap connected thereto and adapted to be wound about the same and tobe unwound therefrom as said member rotates in opposite directions, andan inherently elastic friction member which is caused by the strap tofrictionally engage the rotary member when the strap is unwound from thelatter and which automatically releases itself from the rotary memberwhen the strap is wound about the In testimony whereof, I hereuntoaflixmy signature.

JACOB R. SNYDER.l

